[Crowdsourcing] Fix 2 critical errors with static turn annotations

[EricMichaelSmith]

Patch description

• Fixes frontend error in static_turn_annotations, caused by frontend supplying a temporary taskData object in the interim transitioning between onboarding and the full world
• Fixes the issue that the final submitted data needs to be part of a dict with a 'final_data' key

(thanks @JackUrb for the fixes!)

Testing steps

python parlai/crowdsourcing/tasks/turn_annotations_static/run.py \
conf=test00.yaml \
mephisto.database._database_type=singleton \
mephisto.log_level=debug \
mephisto.task.maximum_units_per_worker=100000 \
mephisto.blueprint.onboarding_qualification=test_2023_02_17__04 \
--config-dir ${DIR}`

[meganung]

lgtm :)